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X-12 Microphone Preamp Kit
USING DISCRETE OPAMPS
You may also use discrete opamps instead of the supplied PDIP8 opamp chip in the kit for IC1. Whether discrete opamps (DOA)
are better than today’s current IC chip designs is up for debate. Let your ears (and pockets) decide.
Either way, there is
provision on the board to use either discrete opamp or PDIP8 chips.
You’ll see the big square outline of a Discrete OpAmp chip on the PCB, with pads for IN-, IN+, OUT, V-, GND and V+
You have (2) Options for assembly:
Option A. Use Socket Pins for IN-, IN+, OUT, V-, GND and V+ pads. The Discrete Opamp pins are then inserted into the sockets.
(Note: Millmax DOA Socket pins are not provided in the kit, but may be purchased separately. Contact us.)
Option B. Solder the OpAmp directly to the board. (If you’ll be using Yamaha Discrete Opamps, this is your only option.)
OPTION A
This is the recommended method if you’ll be using the typical 2520/990 discrete opamp. If you’ll be doing Option A, i.e. using
Millmax DOA Socket pins, you can solder the PDIP8 IC socket, Cf, C10, C11 and R27 in their original locations on the PCB.
OPTION B
If you won’t using Millmax DOA Socket pins, you can solder the Discrete OpAmp directly to the board. Note that this is more
risky and will also be more difficult to remove the opamp from the board later.
